Transcutaneous aortic valve implantation

Non-rheumatic, degenerative aortic stenosis is overwhelmingly a disease of the elderly. As many as 300,000 individuals in the United States have symptomatic aortic stenosis (AS). Prior studies suggest that patients with asymptomatic but hemodynamically significant AS have a high risk of dying or developing symptoms. A Mayo Clinic study demonstrated that the 1, 2, and 5 year probabilities of remaining free from operation or death were 80%, 63%, and 25% respectively in a cohort of 622 patients (Pellikka et al. 2005). The development of symptoms portends a high risk of death (Carabello 2002). Surgical intervention with mechanical or tissue prosthetic valves has long been the gold standard for treatment. Improved operative techniques and more durable valvular prostheses have resulted in excellent functional status and patient survival. While operative mortality at experienced centers with careful patient selection is low, frequently patients with calcific AS have increased operative risk (OBrien et al. 2009). As such, a third to half of elderly patients with symptomatic AS are not candidates for operative intervention due to advanced age or severe co-morbidities (Bouma et al. 1999). Percutaneous aortic balloon valvuloplasty has not resulted in long-term relief, with early restenosis the rule.